/*
 * Copyright 2008 Christopher Davies
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *     http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.googlecode.textish.tokenizer;

import java.util.Iterator;
import java.util.List;

/**
 * Tokenizes a list of {@link CharToken}s to a list of {@link CharToken}s and
 * {@link WordToken}s.
 * 
 * @author cgdavies
 * 
 */
public class WordTokenizer implements ITokenizer {

	public void tokenize(CharSequence context, List input, List output) {
		TokenBuilder wordBuilder = WordToken.createBuilder();

		for (Iterator it = input.iterator(); it.hasNext();) {
			IToken token = (IToken) it.next();

			if (token instanceof CharToken) {
				char ch = context.charAt(((CharToken) token).getStartIndex());

				if (Character.isWhitespace(ch)) {
					IToken wordToken = wordBuilder.build();

					// If we were building a word, append it before the
					// whitespace character.
					if (wordToken != null)
						output.add(wordToken);

					output.add(token);
				}
				else
					wordBuilder.append(token);
			}
			else
				throw new UnexpectedTokenException(token.getClass());
		}
		
		IToken wordToken = wordBuilder.build();
		if (wordToken != null)
			output.add(wordToken);
	}

}
